Air-pump



UNITED sTATEs PATENT oEErcE.

CHARLES REEDER, OF BALTIMORE, MARYLAND.

AIR-PUMP Usiinrn` Low-.PRESSURE 0Ry coNnENsrive STEAM-ENGINES.

Specification of Letters Patent No. 3,334, dated November 15, 1843.

To all whom t 'may concern Be it known that I, CHARLES REEDER, engineer, ofthe city of Baltimore, in the State of Maryland, have made, certain new and useful Improvements in the Manner of Constructing the Air-Pumps Used in Low- Pressure or Condensing Steam-Engines, by means of which improvements said fairpump is ina-de to operate more efficiently, in proportion to the power expended,` than eitherl the double or single acting air-pumps previo-usly in use;` and Ido hereby declare that thefollowing a `full and exact description'thereof. i i

Figure l, in the accompanying drawings, is aperspective view of my improved pump, and its immediate appendages; and F ig. 2, is a verticalv sectioni of the same in the plane of the axes of the air-.pump andcondenser;

in each of these gures the same parts are` designated by the same letters of reference. A, is the condenser, which is a cylindrical, or other formed, vessel of cast-iron.

B, is the air-pump, the upper `part of which is connected with the condenser by means of the air-pipe, C. The condenser and air-pump both rest on the cast-iron plate, or seat, D, D.

S, S, are sills which are represented as placed under the plate D.

Between the condenser and the air-pump, at their lower ends,is a foot valve E, which opens toward the airpump, as represented; and in the upper part of the airepipe, C, there is an air valve V, also opening toward the airpump.

T, T, are the bonnets which valves.

F, is the piston, or bucket, of the air pump, furnished with butterfly valves, as shown at Y, which are regulated in their rise by the guards, G. `The piston rod P, and the stuffing boX, X, are formed and ar ranged in the ordinary manner. w,

O, is the opening for admitting the steam from the engine into the condenser. H, the

cover these discharge valves through which the air and water are to pass from the air-pump into the discharge box, J I, a discharge tube for the escape of water from the said box.

Itvwill be readily seen by every competent machinist that there is not anything newin either of the partsabove described, when taken individually; but it will be found upon a. careful examination of the manner in which these parts are arranged, and combined' with-each other, that a new, and very useful, effect is thereby produced. The piston, or bucket, of thev air-pump is made on the same plan` with that of the ordinary singleacting air-pump, but in its operation it will be found that my pump is doublew acting. The cylinder of this `pump I make from five to siX tenths the diameter of the steam, or main, cylinder of the engine, and it has one half the length of the stroke. This length and diameter may, of course, be varied, provided this is done without changing the ratio which the capacity of the airpump bears to that of the main cylinder. Betweenthe'top of the piston, F, and the apof the pump, there isa water space, the content of which is not to be discharged.

The operation of this improved pump is as follows. The piston on its ascent, forms a vacuum below it, in the usual way, and the water, with a portion of the air and vapor, will pass from the co-ndenser, as in the coinmon double, or single, acting pump. `On the descent of the piston, a partial vacuum will be immediately formed above it, as its valves will be keptclosed, not by their own gravity, merely, but by the pressure of the portion of water above them, which, from the arrange ment of the parts, was not discharged in thef` upward stroke. This will consequently pro duce a partial vacuum above the piston, and the air and vapor in the condenser will consequently Vopen the Valve V, and will pass into the upper `end of the pump cylinder. The valve V, it will be seen, is situated,like

thatV of the ordinary double-acting airi pump; that is to say, as near to the upper part of the structureas possible. When the piston, in its descent, is brought into contact with the `water contained in the lower part of the pump, the valves in the piston will openr with unusual ease, in consequence of,

The advantages of this manner of construction and operation are, in part, as fol lows. It is less in its proportionate diameter than the ordinary air-pump, which is equal to seven tenths of that of the main cylinder, while mine need not, as herein stated, be more than live, or between tive and six, tenths of such diameter; from this circumstance alone, there is less loss by 'riction than in the ordinary pump; it produces an equal vacuum above and below its piston, both in itselfl and in the condenser, at each stroke, which the common single-acting pump cannot effect. By having a valved piston, or bucket, it is entirely free from the most serious objection to the solid piston of the double-acting pump, the lat-ter in its descent striking the water with a force nearly, or quite, equal to that due to its collision with a solid body, and producing a concussion equally unpleasant and injurious, sometimes breaking the valves, or bonnets. The water vis discharged, also, with much greater ease in my pump than it possibly can be in the down stroke of the doubleacting pump, the foot valve of which has to open against the pressure of a very considerable column of water.

Having thus -fully described the nature of my improvements in the air-pump for condensing steam engines, what I claim therein as new, and desire to secure by Letters Patent, is-

rl`he manner herein set forth of arranging the valves of the pump and condenser, and of connecting and combining them with each other, so as to render the said pump doubleacting, while its piston is provided with valves, as in the common single-acting airpump; that is to say, l claim the arrangement of the air-pipe C, with its valve, V, opening into a water space between the upper side of the piston, F, and the head of the cylinder, in combination with the valved piston, the foot` valve, E, and the discharge valves, H; by which arrangement and combination the apparatus is made to operate as herein set forth.

I have already stated that I do not claim either ot' the individual parts as new, and consequently, limit my claim to the combi* nation as a whole, but wit-hout intending to limit mysel'tl to any particular form of the respective pai'ts, but to extend it, under all variations of form, to every combination which is substantially the same in its manner of action, and in the result produced.

CHAS. REEDER.

lVitnesses Trios. l. JONES, B. K. MonsELL. 

